Machine for grinding hobs, milling-cutters, and the like.



1 P. BROWN & P. J. BOSTOGK. MACHINE FOR GRINDING HOBS, MILLING GUTTERS,AND THE LIKE.

APPLICATION FILED 00T.8, 1913.

1,100,528, Patented June 16, 1914.

3 SHEETS-SHEET 1.

P. BROWN & F. I. BOSTOCK. MACHINE FOR GRINDING HOBS, MILLING GUTTERS,AND THE LIKE.

APPLICATION FILED coma, 1913.

1,100,528, Patented June 16,1914.

3 SHEETS-SHEET 2.

P. BROWN & F. J. BOSTOOK. MACHINE FOR GRINDING HOBS, MILLING GUTTERS,AND THE LIKE.

APPLICATION FILED 0OT.8, 1913.

1,100,528, Patented June 16,1914.

3 SHEETSSHEET 3.

PERCY BROWN AND FRANCIS JOHN BOSTOCK, F HUDDERSFIELD, ENGLAND.

MACHINE FOB GRINDING HOBS MILLING-CUTTERS, AND THE LIKE.

Specification of Letters Patent.

Patented June 16, 1914.

Application filed October 8, 1913. Serial is. 794,051.

To all whom it may concern:

Be it known that we, PERCY BROWN and FRANCIS JOHN BOSTOCK, subjects ofKing George V of Great Britain, residing at I-Iuddersfield, in thecounty of York, England, have invented certain new and usefulImprovements in Machines for Grinding Hobs, Milling-Cutters, and thelike, of which the following is a specification.

Our invention relates to machines for grinding'hobbing cutters, ormilling and the like cutters and has for its object to provide animproved and simplified construction of machine for the purpose.

In describing our invention we shall refer to the accompanying drawingsin which- Figure 1 is a rear elevation of a machine constructedaccording to and embodying the invention; Fig. 2 is an elevation lookingin the direction of the arrow A, Fig. 1; Fig. 3 is a partial plan Viewof the machine; Fig. 4-is a detail, on an enlarged scale, of theabrasive wheel head; Fig. 5 is a section on the line BB, Fig. 4, andFigs. 6 and 7 are detail sections illustrating the dividing mechanismfor the cutter supporting spindle.

Referring to the drawings, our improved machine comprises a suitablestandard or frame 1 havinga guide 2 on which is vertically movable aslide 3. A cross slide 4, Fig. 2, operated by screw 5 and hand wheel (3,carries a universal head 7 supporting the abrasive wheel 8 which has itsupper side or face profiled to suit the tooth to be ground. A lateralextension 9 on the standard 1 supports a dished table 10 having acentral boss 11 forming a bearing for a Vertical sleeve 12, Fig. 6, inwhich the hob or cutter supporting spindle 13 is carried.

The slide 3 has pivotally connected to "it one end of a link 14 whoseopposite end is pivotally mounted on a pin or stu 15 ad justably securedin a slot 16 in a rotatably mounted disk 17. Integral with or attachedto the disk 17 is aspur wheel 18 which is adapted to be engaged anddriven by a pinion 19 carried by a lever 20. A pulley 21 fast on theaxis of the pinion 19, and driven by belt from any convenient source,serves to impart motion to the pinion. The lever 20.1is pivotallymounted at 22 and a spring 23 acting on said lever on the opposite sideof the pivot center to the pinion 19 acts' to maintain the pinionnormally in mesh with the gear 18, an adjustable stop 24 being providedto engage the lever and limit the upward movement of the pinion. Thefront end of the lever is provided with a foot plate or pedal 25,pressure on which causes the'lever to be rocked against the action ofthe spring 23 and to withdraw the pinion 19 from engagement with thegear 20. So long as the pinion 19 and gear 20 remain in mesh the slide 3is reciprocated and a vertical reciprocatory motion is imparted to theabrasive wheel 8, and on the withdrawal of the pinion 19 the slideceases to be driven. It is advantageous that the slide be brought torest when desired with the abrasive wheel in a certain position, that isto say clear of the hob or cutter and to this end the lever 20 isprovided with a block 26 which. is adapted, on the lever being rocked towithdraw the pinion 19, to engage the periphery of the disk 17 and toenter a recess 27 therein.

The head carrying the abrasive wheel comprises a dished casting 28mounted to swivel on the end of the cross slide 4. A carrier 29,supported in an opening 'in a boss 30 on the casting-28 is provided withball and thrust bearings 31 to support a spindle 32 on which theabrasive wheel 8 is secured. The carrier 29 is slidable up or down in anopening in the boss 30 to adjust the height of the abrasive wheel. Theupper end of the spindle 32 carries a pulley 33, to which motion istransmitted, from a driven overhead pulley not shown mounted on acounter-balanced arm, by a cord or belt which passes between and isguided by guido pulleys34 and 35 carried by an arm or extension 36 on orsecured to the upper end of the carrier 29. ..The boss 30 is split at 37to enable the carrier to be gripped in the desiredposition by means ofstud 38. The

I abrasive wheel 8 can thus be caused to occupy, and be driven in anydesired position while being at the same time raised and lowered; i.

In the case of a hob, or of a milling cutter in which the face of thetooth to be ground is spiral in form, rotation of the hob or cutter togive the desired lead is effected as follows:The slide 3 has formed uponit a vertical rack 39, Fig. 3, which meshes with a pinion 40 fast on ashaft 41. suitably supported in bearings 42, 42. Fast on one end of theshaft 41 is a gear 43r.which meshes,

through change gears 44 and 45, with a gear 46-fast on a shaft 47supported in suitable hearings in the frame'beneath the table 10. I theweight of theslide 3 and the parts car- Through indexing or dividingmechanism, which will be described later, motion is conveyed from theshaft 47 to a spiral gear 48 fast on the sleeve 12 which carries the hobor cutter supporting spindle 13. As the slide 3 causes the abrasivewheel to move up and down, therefore, the hob is rotated first in aforward direction and then in a backward direction, the desired leadbeing effected by the change gears 44 and 45.

The indexing of the hob or cutter or the presentation of a fresh tooththereof to the *abrasive wheel when one tooth has been ground iseffected as follows :The shaft 47 has fast upon it a peripherallynotched disk 49, one or other of the notches of which is adapted to beengaged by a spring plunger 50 carried by a casing 51. Mounted on aspindle in the casing is a worm 52 which meshes with a worm wheel 53fast on a sleeve 54 on which is formed or secured a spiral gear 55meshing with the gear 48 on the sleeve 12. On withdrawal of the plunger50 clear of the disk 49 the casing 51 can be rotated by means of handle56 to the extent of as many notches as may be required, the rotation ofthe casing, as

will be understood, causing the hob or cutter spindle, through thesleeve 54, gears 55 and 48 and sleeve 12, to be rotated through thedesired portion of a revolution to present a new tooth of the hobopposite the abrasive wheel. Independently, rotation of the worm 52,which can be effected by means of a lever or handle 57 on its spindle,enables a fine adjustment to be given to the hob relatively to theabrasive wheel to determine the depth of cut.

The disk 17 which is rotated in the direction of the arrow C, Fig. 1,has its center offset from'the line of movement of the slide 3, theeffect of which is to cause a slow upward or cutting movement of theslide and consequently of the abrasive wheel, and a quick downward oridle movement.-

Since, by means of the rack 39, and the intermediate gearing, the slide3 effects the backward and forward rotation of the hob or cutter, itfollows that the speed at which the said hob or cutter is' rotated willvary with the speed of the slide, and the correct relative speeds of thehob or cutter and of .the abrasive wheel be always maintained.

The connection between the link 14 and the sleeve 3 is through a block58 which is adjustably secured in a slot, not shown, in the slide, toenable the timing of the stroke of the slide to be adjusted.

For a hob or cutter whose teeth form left handed spirals the abrasivewheel would be reversed.

A pulley 59 fast 'on the shaft 41 has connected to its periphery a chainor the like 60 supporting a weight 61 to counter-balance ried thereby.

The machine can be advantageously employed for grinding ordinary millingand like cutters in which case one of the gears 43 or 44 would beremoved or slid out of mesh to allow the spindle 13 to remain stationaryinstead of rotating forward and backward as above set forth.

An opening 62 in the table 10 permits the lubricating water employed todrain away through suitable passages, not shown, to a combined tank andpump (53 from whence it is returned to the hob.

The vertical arrangement of the hob or cutter spindle as herein setforth presents many advantages of a practical nature over the horizontalarrangement hitherto adopted.

Having thus described our invention, what we claim as new and desire tosecure by Letters Patent is 1. In a grinding machine, the combination,with a reciprocating slide, and a rotary grinding wheel carried by thesaid slide;

of a crank-disk and a connecting-rod for reciprocating the slide, atoothedwheel secured to the crank-disk, a pivoted lever, and a tootheddrivin pinion carried by the lever and journaled eccentric of its pivotand normally engaging with the said wheel, said lever and crank-diskbeing provided with interlocking portions which are moved intoengagement to stop the slide when the pinion is *moved out of engagementwith the wheel.

2. In a grinding machine, the combination, with a reciprocating slide,of a head carried by the slide and provided with a bearing, a carrieradjustable longitudinally inthe bearing, means for clamping the carrierin the bearing, antifriction shaft bearings arranged in the saidcarrier, a shaft journaled in the antifriction bearings and providedwith means for revolving it, and a grinding wheel secured on the saidshaft.

3. In a grinding machine, the combination, with a reciprocating slide,and a rotary grinding wheel carried by the said slide; of a spindle forsupporting the article to be ground, and intermediate driving mechanismoperatively connecting the said slide and spindle so that the'spindle isrevolved termediate driving mechanism 0 eratively connecting the saidslide and spin le so that the spindle is revolved first in one directionand then in the other to correspond with the reciprocating movements ofthe slide and the grinding wheel.

5. In a grinding machine, the combination, with a rotary grinding wheel,and driving devices for reciprocating it; of a supporting frame, arotary spindle, for carryin the article to be ground, mounted in theframe, a spiral gear wheel operatively connected with the said spindle,a shaft journaled in the frame and provided with driving mechanism forrevolving it, a sleeve mounted on the said shaft, a spiral gear wheelsecured to the said sleeve and engaging with the aforesaid spiral gearwheel, a spacing disk secured to the sald shaft, and a casing connectedwith the said sleeve and provided with a disengageable locking devicefor engaging with the spacing disk, so that the casing and sleeve can berevolved by hand to adjust the position of the rotary spindle and thearticle when the casing is unlocked from the spacing'disk.

6. A machine for grinding hobs, or millingand like cutters in which anabrasive wheel is carried by a vertically reciprocating slide having aslow cutting stroke and a quick return stroke, the said slide carrying arack which operates means for rotating the hob or cutter, whereby thehob or cutter is rotated first in one directioncand then in the other ata speed varying with that of the vertical movements of the abrasivewheel, substantially as herein shown and set forth.

7. A machine for grinding hobs or milling and like cutters comprising astandard,

a slide movable vertically thereon, means'to operate said slide to givea slow cutting movement anda quick return movement, a cross slidecarrying a universal head sup porting an abrasive wheel, means to drivesaid abrasive Wheel, a hob supporting spindle, and means includinindexing mechanism to cause the hob to ie rotated forward and backwardat the required speed relatively to the rate of upward and downwardmovement of the abrasive wheel, substantially as herein shown and setforth.

8. Ina machine for grinding hobs or milling and like cutters thecombination with a vertically movable slide carryin an abrasive wheelhead, of a link pivotal y connected to the slide and to a rotatabledisk, whose center is offset from the line of movement of the slide, agear rotatable with the disk, a pinion carried by a pivoted lever, meansto drive the pinion, a spring acting on the lever to normally hold thepinion in mesh with the gear on the disk, and a block carried by thelever and adapted, on the lever being rocked to withdraw the pinion frommesh with the gear, to enter a recess in the periphery of the disk andcause the slide carrying the abrasive wheel to come to rest in adefinite position, substantially as herein shown and described.

9. In a machine for grinding hobs or milling and like cuttersthecombination, with a vertically reciprocating slide and a cross slidemounted thereon, of a dished casting mounted to swivel on the endofvsaid cross slide, a carrier slidably supported in an openm in a bosson the casting, ball and thrust bearings within said carrier supportinga spindle on which the abrasive wheel is secured, a pulley fast on saidspindle and guide pulleys carried by an arm attached to or integral withthe carrier, all substantially as herein shown and set forth.

In testimony whereof we aifix our signatures in the presence of twowitnesses.

Witnesses:

T. E. WHITELEY, C. E. HINCHLIFF.

